Three areas of the chemistry of N-hydroxypyrazoles are being investigated: 1) Electrophilic substitution reactions as to their scope and the utility of the products for the synthesis of novel heterocycles. 2) The synthesis of bipyrazole analogs of the N-hydroxypyrazoles with particular emphasis on the use of diazopyrazoles and diazopyrazole oxides as the building blocks. 3) The scope of the oxadiazinone N-oxide (oxidation products of 1,4-dihydroxypyyrazoles) - acetylene cycloaddition reactions for the synthesis of butenolide derivatives.